In this application we propose to develop a simple and economical method for producing protein-display beads using a novel approach to controlling diffusion. Each bead will carry a different DNA sequence and the protein encoded by that sequence, and the method will produce beads carrying hundreds of millions of different sequences in a single reaction. The beads will be used in a new, extremely high-throughput technology for studying protein function. This new approach combines the data-intensive style of genomics and elements of sequencing technology in a way that can be routinely applied to many different proteins. We plan to commercialize the technology by using it to characterize and optimize proteins of medical and industrial value. We will provide the functional characterization of proteins as a new service for our existing customers in the biotechnology and pharmaceutical industries, and use the technology on internal research projects aimed at developing new industrial and therapeutic proteins. The protein-display beads can also be used in a selection for superior proteins from a pool of protein variants, This could itself be the basis for new products for our company.